Ventilated blackboard installation



J.. F. JOH NSON VENTILTED BLACKBOARD lusTAmJA'rIoN` Filed sept. 11, 1928Dec. 16, 1930.

Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE JOHN F. JOHNSON, OFCHICAGO HEIGHTS, ILLINOIS, ASSIGNOB, TO WEBER COSTELLO COMPANY, OFCHICAGO HEIGHTS, ILLINOIS, A CORPORATION OF ILLINOIS VENTILATEDBLACKBOARD INSTALLATION Application led September 17, 1928. Serial No.306,530.

This invention relates to blackboards and particularly to theinstallation of the same, whereby the boards may be ventilated toprevent sweating, or the collection or condensa tion of moisture on theblackboards and to keep the same dry, especially in humid climates, sothat the boards may be properly written on with blackboard crayon andreadily and thoroughly cleaned by the ordinary blackboard erasers.

I have found that all blackboards sweat' and become damp in humidclimates, necessitating the replacement ofv the boards at much expenseand because of the dampness chalk marks are very indistinct 'and cannotbe properly made and completely erased.

l have overcome the above objections by Ventilating the blackboard insuch a manner asto permit circulation of airbehind the board so that thesame will remain dry even in very humid climat/es, and as a result thechalk marks may be properly made and erased. v A

An object of the invention is to provide a blackboard installationwhereby the blackboard will not sweat.

f Another object of the invention isto provide a blackboard which willremain dry soy that chalk marks may be properly made so that they areeasily removed and completely erased.

A further object is to provide a blackboard which may be used in anyclimate without sweating, and which remains dry under all circumstances,and one which may be economically installed.V

When chalk or crayon marks are made on a damp or wet blackboard, thenature of the ingredients of the crayons is such as to cause theparticles left on the board, from the chalk or crayon, to` becomecemented tothe blackboard with the result that a scum or film forms overthe surface. This renders the writing surface valueless, and must beremoved to restore the Writing surface. By

Ventilating the blackboard, as is the object of l this invention,sweating and the condensa'- rial which is superimposed upon the furringstrips.

One form` of the invention is illustrated in i the accompanyingdrawings, and the' views thereof are as follows:

Figure 1 is a fragmental perspective view of a wall showing a blackboardsecured thereto, .in accordance with this invention.

Figure 2 is an enlarged vertical section through Figure 1. l

Figure 3 is an enlarged horizontal section. There is shown in Figure 1aportion of a. wall 1 having the usual baseboard 2 along the floor. Theblackboard 3 is secured to the wall 1 in the following manner:

Horizontal headers or grounds 4 and 5 are secured to the backing 6 ofthe wall so as to lie flush with the surface of thev finish 7. Plasteronothe wall behind the blackboard is not essential as the horizontalleaders of grounds 4 and 5 can be put on the studding, lath, brick orsuch other material as may be used for the Wall. Vertical or horizontalfurring strips 8 are attached to the headers 4 and 5 at spacedintervals. Plastic material tions to adhere and thus be held firmly inposition.

The blackboard sections 3, when the blackboard is a long one, may havethe adjacent ends of several sections covered byan overlap or connectingstrip 10 to improve the appearance of the board. The blackboard may alsobe joined by'what is known as a butt joint.

A. frame comprising vertical members 11, top horizontal members 12 andlower horizontal members 13 may be constructed so as to provide a finishfor the blackboard but not so as to close the air spaces behindthe'board.

A cork insert 14 may be axed along the `upper part of the board for useswell understood.

The spaces formed between the furring I strips 8 are openat the top andbottom so as to permit free circulation of air behind the board. Whenhorizontal furring strips are used, the openings will be the ends of theboard. Circulation of air' through these spaces keeps the board dry2thus preventing sweating and also preventing formation of chalk scumthereb preventing the xchalk marks from becomlng indistinct. v

, While I have described more or less precisely the details ofconstruction of my invention, yet I do not wishto be understood aslimiting myself thereto, as I am aware that changes may be made in the`arrangement and proportion of parts and equivalents may be substituted,all without departing from the spirit and scope of my invention.

-I claim as my invention:

1. In combination in an apparatus for su porting a blackboard of thewall ltype sole y by a wall in such a manneras to preclude the depositof sweat on the board as a result of its proximity7 to the wall and tothus preclude l the formation of chalk scum of the character describedthereon, strips for spacing vthe board from the wall and additionalsupporting means for the board in said spacing arranged to definesubstantially vertical passageways to allow afnatural draft ofatmospheric air to circulate through each of the passageways. y

` 2. The combination with a blackboard of the wall type of means forlsupporting the board on a wall in such a manner as to preclude thedeposit of sweat on the board as a result of its proximity to the wall,including spacers between the board and the wall arranged to definesubstantially a vertical passageway for causing a natural draft ofatmospheric air to circulate between the wall and the board. Intestimony whereof I have hereunto subscribed my name at Chicago Heights,Cook County, Illinois.

JOHN F. JOHNSON.

